Alarm apparatus



A. H. JURGENSEN. ALARM APPARATUS.

APPLICATION FILED APR. H, 1919.

Patented Sept. 27,1921,-

UNITED STATES PATENT FHCE.

ALARM APPARATUS.

Specification of Letters Patent.

Patented Sept. 27, 1921.,

Application filed April 11, 1919. Serial No. 289,398.

To all whom it may concern:

Be it known that I, AAGE HALFDAN J on- GENSEN, a subject of the King of Denmark, residing at Lyngby, near Copenhagen, in the Kingdom of Denmark, have invented certain new and useful Improvements in Alarm Apparatus, of which the following is a specification.

The present invention refers to an alarm apparatus in case of burglary, fire, and the like, being devised for use in connection with previously installed telephone lines, so that the apparatus, in case of alarm, rings up the central telephone exchange, where, after investigating the nature of the signal, the operator informs the police, fire-department, or the like, according to circumstances. Thus this alarm apparatus only requires a local installation of wires to the requisite contactqnembers in the room or rooms, or the like, to be protected, and it is furnished with members which, in case of either ordinary closing of contact or injury to the wiring, e. g. the cutting of the wires, cause the release of a mechanical force which as in telephone apparatus, opens or closes a ringing-current.

One form of construction of this deVlud applied in connection with a telephone installation with magneto-telephones, is diagrammatically shown on the drawing, which is a side-view of the apparatus, with part of the outer wiring.

In a suitable case there is disposed a set of horseshoe magnets a with armature I), which is secured to a shaft 0 supplied with a hand-crank. To the shaft cis secured one end of a spiral spring (Z, the other end of which is held fast to the supporting frame of the shaft by means of a nut 7. The shaft 0 carries a wheel 6 with a notch g in its periphery, into which notch enters the hookshaped arm h on a three-armed lever, when the spring (5 is wound, the book It normally preventing the shaft 0 from turning under the influence ofthe spring. A second arm j of the said lever which is pivoted at i carries an armature for an electro-magnet is, which, when active, attracts the armature, so that the arm h is disengaged from the notch 9.

Above the third arm m of the said lever there is disposed a one-armed lever 0 turn able on a pin a in a standard 9, said lever being actuated by a helical spring p fastened to the standard, which spring tends to move the lever 0 down toward the arm m. The lever is normally held in position above the arm m as shown by means of a rod 9, of insulating material, which carries a hook s, which extends up through a suitable opening in a safety-plug u and grips around the filament fuse t disposed in this safety-plug, which is held fast in the standard Q.

The winding of the electro-magnet 7c is, by means of a conductor '1, connected with one pole of an electric current source 4;,

which,e. 9., may be the battery used for the tel'ephone'apparatus, the other pole of the battery being connected with a conductor 2 which, over a terminal 3, is carried out into the room or rooms to be protected and is here connected with one of the two parts of the contact members M, which are, e. 9., placed in doors, windows, money-safes, and the like, or on the ceiling (to close the current in case of fire). The other end of the winding of the electro-magnet is, by means of a conductor 4, through a terminal 5, connected with the other part of the contact members to, so that the current through the electro-magnet 70 from the battery 1) is closed whenever one of the contact members to is closed. This results in the armature attracting the lever-arm 9', so that the shaft 0, actuated by the spring cl, will turn.-, The current induced into the armature by the turning of the armature b is carried through conductors 10 and 11, respectively connected with the shaft 0 and with a terminal y, which, in turn, by means of a drag-spring, in a well known manner, are conductively connected with the armature, to the telephone conductors. In the conductor 10, there is inserted a switch a so that the alarm apparatus can be thrown into and out of action when desirable.

In order to prevent the alarm apparatus from being put out of action by cutting the conductors 2 and 4, whereby the contact members to can be closed without current passing through the electro-magnet k, two high-voltage conductors, 9 and 7 respectively, are run parallel to the conductors 2 and 4:, e. g. from a light-contact 8 and 6. The conductor 9 is connected with the two ends of the fuse 25, so that the latter is included in the circuit of the high-voltage current. Now when the main which supplies all the conductors 2, 4, 7 and 9 is out, not only the conductors 2 and 4 are short'circuited, which will not always be sufficient to set the electro-magnet is into action, but also the high-voltage conductors 7 and 9, causing the fuse t to be melted. Thereby the hook s and the lever are released, the latter, under the influence of the spring p, striking down against the leverarm m, so that the arm h is removed from the notch g, and the Wheel 6, on the shaft 0, is released. Thus the alarm apparatus will, in all cases, be sure to act When the switch m is closed.

I claim 1. Alarm apparatus adapted to be inserted in the wiring of a telephone installation, comprising in combination with a local electric circuit, a movable member for producing an electric current causing the alarm, ameans tending to operate said member, a locking means normally holding said member in inoperative position, a plurality of con tact elements in said electric circuit, adapted to be automatically closed, a second electric circuit adapted to be short-circuited upon the cutting of the Wires in the said first circuit, and means independent of each other included in each circuit and adapted to disengage the said locking means releasing the said movable member upon any of the said circuits being closed.

2. An alarm apparatus comprising in combination with a local electric circuit, a movable member adapted to produce an electric current for causing the alarm, a spring tending to operate said member, a locking means normally holding said member in inoperative position, a plurality of contact members in said electric circuit, adapted to be automatically closed, an electromagnet arranged in said circuit to disengage the said locking means upon the said electromagnet being energized by the closing 01": any of the said contact members, a second high-voltage circuit adapted to be short-circuited upon the cutting of the Wires in the said other circuit, a fuse in said high-voltage circuit, a springcontrolled lever adapted to disengageisaid locking means, but normally held in inoperative position by said fuse, the latter upon the said high-voltage circuit being short-circuited being melted thereby releasing the said lever to disengage the said locking means.

In testimony whereof I allix my signature in the presence of two Witnesses.

AAGE HALFDAN JoRGENsEN.

Witnesses:

N. BUsoH-JnNsEN,

EWELL Snow. 

